如何在fork()之后将命令行参数传递给子进程

Question

我有以下代码草案.

#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>    

int main(int argc, char *argv[])
{

    printf( "usage: %i filename", argc );

    pid_t pID = fork();
    if (pID == 0)                // child
    {
        // Code only executed by child process
        printf("Child PID: %i", pID);

        int file = open("/tmp/rtail", O_CREAT | O_WRONLY);

        //Now we redirect standard output to the file using dup2
        dup2(file,1);

        char tmp[30];
        sprintf(tmp, "cat `tail -f %s`", argv[1]);
    }
    else if (pID < 0)            // failed to fork
    {
        printf("Failed to fork");
        exit(1);
        // Throw exception
    }
    else                                   // parent
    {

    }

    // Code executed by both parent and child.  

    return 0;
}

如何将命令行参数传递给子进程？例如,./app alch.txt我想要跑步

sprintf(tmp, "cat `tail -f %s`", argv[1]);

生产

cat `tail -f alch.txt`

在tmp.

Answer 1

如何将命令行参数传递给子进程？

你不需要做任何特别的事情; fork确保每个进程获取所有局部变量,包括argv.